udhcpd: account for script delay in lease

Prevent nasty surprises if script runs longer than lease time / 2.

Signed-off-by: John Schroeder <jschroed@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index a34829c3a..9d3d1a31c 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -1752,7 +1752,6 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                 }
 #endif
                                 /* enter bound state */
-                                timeout = lease_seconds / 2;
                                 temp_addr.s_addr = packet.yiaddr;
                                 bb_info_msg("Lease of %s obtained, lease time %u",
                                         inet_ntoa(temp_addr), (unsigned)lease_seconds);
@@ -1761,6 +1760,11 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                                 start = monotonic_sec();
                                 udhcp_run_script(&packet, state == REQUESTING ? "bound" : "renew");
                                 already_waited_sec = (unsigned)monotonic_sec() - start;
+                                timeout = lease_seconds / 2;
+                                if ((unsigned)timeout < already_waited_sec) {
+                                        /* Something went wrong. Back to discover state */
+                                        timeout = already_waited_sec = 0;
+                                }
 
                                 state = BOUND;
                                 change_listen_mode(LISTEN_NONE);